Pneumatic wheel.



Patend Deo. 11. 1911.

WQH.

Wai-huhu w'. H. MCCAFFREY.

PNEuMmc WHEEL.

APPLICATION FILED SEPT. I5, 1915.

UNITED eTATEe PATENT: ernten;

WILLIAM HNRY Mamme-EY, er mnmrrefnnin, ALAEAMA, Assumere, on enntfmtn 're It. D. .interferon Jn., er nrnmmeHAm/r, ,Athen-Mn Application filed September 15,'1915. Serial No. .WHQL

To au whom it may comer/n: A

Be it known that I, WILLIAM ll. lli/IUGM?"- iinny, :L citizen of the United Statee oiAlnerien, residing :1t llirlninglnun, in the county of Jefferson :nul State 0l Alnlimmn, have in,- venteil eert-1in new :md nsetnl Improvements in li'icurnzttic lVheels, of which the ellewingr ie :L Speciention.

My invention 'relates 'to zL-nijmel type et wheel in which the riin is huoynntly elipportetl on conlprceeetl nir Whiith it; nininmined :uitolnntienlly nt the required. pressure for .Sustaining the lend hy the operiiition of the Wheel. It iS my purpose te design n, wheel to give ns nearly as possible the ellleet ol n` inenn'ietic tire while using n metall rirn which muy be priwided with :l Solid rubber trend if desired., In designing :t wheel of this type it is vitally essential. that there shall] he :t practical and strong connection between the huh :intl the rim which will trnnsn'iit the trnction pull. equally 'in either directinm to the riin and will nt the sanne time hrzwe it effectively aguil et lateral tlu'uSt withoi'it interfering with :its buoyant support of the loml.

irl

continuous inner polygenitl rin'l connected" then-:tc :tt pointe :so ne to town hrziecs er struts. The Object oli this; :irrniagement ie te provide :in enter rin'i which, thrmgh li ,i line eiihfstzii'itiiiil iilherent resistance te l "lon mation under the loud or shocks. This ne rangement limite to the enmllcet degree the relative movernex'it for which provision must he made between 'the rim and its Supporting means :10ml cuntemplntee e, -eonr'iel'ieating movement in the inner rim which ie yield-- ingly 'steth preferably hy tlnehpot pistons whiell rifle on the :tir that supports; the rims and .fire shorter than the wheel Spokes so that they :lire mlztpted to imply the initial torque or traction pull from heb to rim, enel vice versa.

A. further feature of my `invention is clirecleil to the provision et effective su]j pmting' menne for the rim. lfn this eonnectifni I here conceived, that 'the outer double rim shoi'iliil be supported 'for limited circumferential movement by short spokes which are pvotally connected to pieton plnngers which y Speimtinn of Letters Patent.

Patented, Detm 1.1Lfb 1.917.

travel in cylinders rigid with the huh. The spokes are radially klisposctl and capable of u limited circumferential play' in the pl ne olf the several spokes hut ere hmeecl leiter-:tl play by the guidee nvt-the ends of the cylinders. This nirrmigeincnt le liatteetl on 'the conception that the trneticm, etrei'n should he equally eveil-able for either direc 'tien of :movement and Slmiilld be equally die tribute-cl aillent the rim While Lthe lnternl thrust on the riin teilten up et pointe on the spokes adjacent to the rim. The joint between the spoke and the rim is preferably one which provides. with. n rninimrun of trieN tion and Strahl for the change in petition of the spoke responsive to n change in ctirecten of the traction pull. or to the ljiiinitecl eecentrie incremente of lthe `riirn unilcr leeft or Sl'loeke.

A further important feature el. my invention rel to the menus 'for hnoynntly sul porting the pieton pluiigere to which the rim spokes nre coiinectel. 'In eoi'ieitlerlng thisphnee of my invention, itisnecessary, hzwiny; in View the economical production of the wheel, to reduce te n rninii'nin'n the number'x ot pninger pistone While nt the seine tinie nilnpting' thein or pnrt of theni to pen forni the ndilitimlnl limiet/ien ef maintain ing thenir pressure upon which the plnngers hiioynntly riden Tethie end ll have signed all of the pieton liiliingere to serre hueyent Snpiorts for the rn'ny zn' lin-ve mlnvpterl one or more et thei'n to perform, the additional function oli mftilitziiningi by n pumping nation, tl i :iii: preetnrc nt the lii'ih reeervoir whieh lnioynntly" ifsiipporte the pl linger.

One vitally importent feature of :ny invel'itien relates to the il :Jaen of the Stor: clminbersfor the eompreeeml eir and these nre preferably ohtziiinecl by providing hill) reecrvoir which subdivided 'into distinct compartments, cach of which receives the Supporting hotly oli :tir for n Tromp @it the Il."

pliilngers so that the enliilivieien or eem-- pnrtnient will :iet ne :in ii'ifle'i'ienilent unit in elistainil'lg its proponi@nnte share of the lonrl. Preferably I provide one ijl'ii'nping; plunger in the group of plnnggere cr erich.

reservoir eoi'i'ipziii."tinent7 though :it *Within` the contenipln'tinn of my invention that twe er `more et the compnrti'nente muy' he inter comicctei'l nnrl provided with cheek; Velvet; so that each pumping plunger muy meinl. ll lli lll) l inder ends-in plan view.

through the joint s tain the pressure in two or more of the compartments and thus simplify the wheel and reduce its cost.

. M l"invention also comprises the various 5 other Vetails 01E-construction and arrangementf'f parts which are hereinafter more particularly described and claimed, and which are illustrated in their preferred embodiment only in the accompanying draw- 10 ings which form a part of this specification,

and in which:-

Figure'l is a side elevation of the wheel with its canvas casing broken away and a number of its cylinders and its hub shown 15 partly in section.

Fig. 2 is a sectional view on the line :v-w of Fig. 1. v

Fig. 3 is a partial plan view of Fig. 1 with the rim broken away to show the cyl- F g. 4: is a detail cross sectional view through one of the plunger spoke joints to the Fig. 5 is a longitudinal sectional View own in Fig. 4. Fig. 6- is a detail view of the combined y relief valve and valve for the charfring of air and oil into the air reservoirs of tthe hub.

Similar reference numerals refer to simi-l lar parts throughout the drawings;

As illustrated, my wheel comprises an outer rinrlV which is corrugated as shown in' cross section Fig, 2 so as to adapt 1t to receive a solid rubber tread 2 and to give 1t the maximum strength for weight. y Within this outer rim is mounted a continuous rim j3 which is made polygonal so thatits sides, beingvdisposed like chords, formha` continuous series of braces or struts which engage and increase the rigidity of the outer rim and brace it against a tendency to become substantially deformed underpressure of the load or shocks, my idea being that the two rims 1 and 3 should be adapted to support the Weight on the wheels by a bodily eccentric movement which would shift their center relatively to the center of the hub rather than by the local indentation or yielding of a flexible rim, The sides of the rim 3 are connected to the outer rim by a series of shouldered bolts 4 having their inner shoulders attened to engage the outer face of the rim 3 and having their outer shoulders 5 slightly curved circumferentially to engage the inner face of the rim 1.

The inner ends of the bolts 4 are threaded and connected by nuts to the rim 3 and nuts 6, having their inner face rounded, connect the outer ends of the bolts to the rim 1, but

it will be noted that this outer end of the bolt is square .and works in an elongated rectangular slot which permits only a limited circumferential movement between the two rims. Midway between these bolts 4 the two rims engage and are connected together by the outerends of the spokes 7. hese spokes are reduced to form square outer ends 8 which pass through and fit snugly between the side Walls of slightly elongated rectangular alining slots in both rims 1 and 3. The ends 8 are turned and threaded to receive each a nut 6 having its inner bearing face curved and shaped also to fit against Vthe grooved center of the outer rim. If desired, the shoulder 9 at the outer end of the spoke can be widened and slightly rounded Where it bears against the rim 3. The square fit of the spoke ends in the slots in the rim issuch as to prevent turning while permitting a limited circumferential play of the rim, which in practice isabout 'an eighth of an inch for the average wheels.

Alternate spokes are connected to pistons 10 working in cylinders 11 and the other alternate spokes rare connected to pistons 12 which work in cylinders 13. These several cylinders have their inner ends tapered and, when cast separate from the hub, their taper ends are threaded and screwed with a tight, rigid fit into threaded taper sockets in the rim of a reservoir 14 through the aXial center of which reservoir passes a tubular integral sleeve 15 which forms the wheel bearing and is adapted to receive any desired type of antifriction bearings. The cylinders 11 are open at their inner ends to the reservoir while the several cylinders 13 have their inner ends closed but are in communication with the reservoir through ports 16. The inner end is left in each cylinder 13 for the purpose of receiving and supporting a pump piston 17 which is bolted thereto and has-its outer end working in a pump barrel 18 movable with a piston 12. The barrel 18 is turned externally and provided with a flat face 18a so that it will makel a sliding but non-turning` fit in a correspondingly shaped opening in a spider 19 which, guides it and its piston 12 and the cylinders 11p are provided each with a spider 2() which receives a flattened guide stem 21 for a piston 10. All' of the pistons are provided with suitable packing rings to prevent leakage as they are all exposed internally to reservoir pressure. On the outer end of cach cylinder I screw a cap 22 having 'therein an elongated narrow slot 23 having rounded ends and made slightly wider than the spoke 7 which passes therethrough and which is pivs otally'connected by a case hardened square headed pin 24 to lugs on the pistons 10 or 12, the pin being held by its square head against turning and' wearing the lugs on the piston` These several caps 22 are braced and connected together by angle bars 25 which are bolted to the side flanges of the cap and eachcap has along each side of the spoke slot raised lugs 25a to increasethe side or lateral thrust bearings for the spoke.

Each piston 12 is bored radially of the to the normal pressure by the safety valve 47. The important function of the dashpots is to yieldingly resist the necessary tendency of the free sides of the inner rim to buckle inwardly when the outer rim becomes deformed or when traction `pull is applied which is done primarily through the dashpot spokes 36 in conjunction with the main spokes 7. The circumferential play allowed 'where the spokes pass through the rims per Init this limited relative movement of the inner rim in either direction. The traction is equally eifectivein either direction; there is a minimum vibration of the buoyantly supported pistons under normal operating con itions, in fact no more than the yielding of a tire under its load; there are no rigid `joints whichwill not provide for the necessary play under extreme conditions of operation; and under all normal operating conditions the load is wholly supported freely and buoyantly on a body of compressed air.

When the wheel( is in service a substantial quantity of oil isy introduced into the reservoir through the chargingvalve ports 48 and this oil is free to fiow into the several cylinders 11 and 13 and also into the several dashpot cylinders so as to effectively lubricate all internal moving bearings in the wheel.

If desired the wheel may be provided with flexible canvas or fabric protecting strips 49 on each side. These strips are annular and are provided vat their outer peripheries with a flap 50 and the inturn edge of the rim lis received in the pocket between the cover and the flap and connected thereto by bolts 51. At its inner periphery the covers are provided with holes Vthrough which draw strings or wires 52 are passed and woven back and forth between the inner taper ends of the cylinders to draw the cover securely about them. Wires and 54 are woven in` circles through the covers and.

sti'en the latter andleavc a fold between them where the cover is intended to flex with the bodily eccentric movements of the rim. In order to hold the covers tight about the cylinders and against flapping, the wires 53 are connected by cross strands 55 which pass over the tops ofthe cylinders.

WhatI claim as new and desire to secure by Letters Patent, is

1. In a wheel of the character described, a central divided compressed-air holder, radial cylinders projectinvr therefrom 4.and communicating therewith, pistons movable in the cylinders, spokes yhinged to the pistons and adapted to swing in the plane of the spokes,l lateral guides for 'the spokes rigid with the hub, a bodily movable rim, and Aa yielding connection between the rim and its said supporting spokes.

2. In a Wheel of the character described,

a corrugated outer rim, a continuous inner rim connected to the outer rim to brace it, the connections between the rims permitting a limited relative circumferential movement7 spokes connected to the rims, pistons hinged to the spokes, and means to buoyantly sup port the pistons under outward pressure.

3. In a wheel of the character described, a rim formed by an outer circular band and an inner polygonal band, means to connect the bands to form a light, rigid, braced rim, spokes connected to the two bands `at their points of contact, means to buoyantly support the spokes and force them radially outwardly from the hub, and buoyant means to resist a buckling tendency of the inner band. 4. In a wheel 'of theV character described, anouter rim formed by a continuous circumferentially corrugated 'strip of metal, rectangular circumferentially elongated slots in the centrally depressed portion of the rim, spokes which support the rim and have squared ends which project through and fit snugly'against the sides of said slots but have limited play endwise of the slots, pistons to which the spokes are hinged, and hub means to buoyantly support thevpistonsY and force them outwardly radially therefrom.

5. In a wheel of the character described, a continuous .circumferentially corrugated outer rim, a continuous polygonal inner rim connected at its corners and braced between its corners `to the outer rim to form strut braces therefor7 said' connections being adapted to permit a limited circumferential movement between the two rims, spokes connected to the rims by being passed through the circumferential slots therein in whichthe spokes have a limited circumferential z comprising spokes connected to the rim, pisi tons hinged to the inner ends of the spokes to permit the latter to swing angularly in a circul'nferential plane of the wheel, cylinders for the plungers having means to confine the livv eccentric movements of the rimto the plane 1 I of the spokes by guides whichV limit the swing of the spokes about the pistons in said plane and brace them against lateral thrust, .neans to resist said angular play of the spokes, and a hollow subdivided hub open to the inner ends ol ythe cylinders and. adapted to be lilled Witl'i bodies of air under pressure.` l

7. In a Wheel of the character described, a hub subdivided and adapted to store com pressed air, a plurality of radial cylinders mounted on the hub and communicating with the storage at the hub and rmtend ing to a point adjacent to the rim of the Wlieel, means to brace the outer ends ot the cylinders together, pistons for said cylinders cxposedto the compressed air at the hub, rigid spokes' hinged to the pistons and extending a short distance beyond the cyliin ders Where they connect to the rim, a sub stantially rigid rim connected to said spokes so as to 'iiierlnit a slight eccentric displacement of the rim relatively to the hubB said spokes under said rim movements being free lor a liinited angular play in the circumiiercntiill plane ot the'wbeel and in either direction.) and guide means rigid with the hub and ad d to engage and brace the ei{ uv e. agains., la! ial thrust.

Br ln a wheel nl' the character described, a hub comprising a d'vided reservoir for holding compressed air1 a plurality' olf radial cylinders opening into said reservoir, pistons movable in. tbc cylinders, a substantially rigid rim.) and seriesot rigid spokes which alone vengage and support the rim `and which are` substantially radially disposed ani" inged to the pistons and -which have a' sligl' `yfielding connection to the rim.

il. ln a "wheel ci the character described, a hub comprising a divided res ervoir for holding compressed air and a plurality oi? radial-cylinders opening there`- Vinto pistons movable in Vthe cylinders, a

substantially rigid rim, a series of rigid. sjgflolrcs minimally 'radially disposed and yieldingly connected to both pistons and rim, said A spoles forming the sole support tor the rim. in all oliits operating positions, means to brace :the spokes against lateral thrust axially of the Wheel, and in strumentalities to both resistand to limit the play of the spokes beyond a, predeter mined point in either direction Ain thefcir ciunllerentialplane of the Wheel.

10. In a Wheel of the character described, in combination, a hub having adivided air reserv'oirz' a plurality ol cylinders communr eating With the hub and radially disposed, a rim, spokes connected to the rim and form'- ing the solo support therefor in all of its operating positions.l pistons hinged to the spolres and adapted tomove in the cylinders, and means operable by thel eccentric body movement of `the rim relative to the hub center to pumplair into said reservoir.

il. In vvheel oit the character described, a hub having a divided reservoir for compressed air cylinders and a series of pistons pressed outwardly by the reservoir presa pistons to a Wheel' rim and having a hinge connection to both rim and pistons to permit therim to have a limited circumferential play in either' direction, and pump means responsive to the relative eccentric displacement between thehub'and rim to maii'ltain the air pressure in the reservoir.

l2. In a Wheel of the character described, an outer rim, an inner polygonal brace rim connected to the outer rim so as to have a limited circumferential play relative thereto, said polygonal rim being continuous and having one or more corrugated portions left free to buckle, a hub, rim supportin means thereon7 and yielding means carrie by the hub and adapted to oppose the buckling of said corrugated portions.

12 In a wheel of the character described, an outer rim, an inner polygonal rim connected to the outer rim to brace it and having a limited circumferential play relative thereto, said polygonal rim being continuousand having one or more corrugated portions left free tobuclrle inwardly, and yielding means connected to the hub and to said ycorrugated portions and adapted to oppose the inward buckling' of said corrugated portions, said means comprising a dashpot having a plunger connected to the inner rim and adapted to exert traction pull thereon.

ich ln aavheel of the character described, a hub having a divided reservoir for compressed air, radial cylinders opening into the reservoir, piston plungers exposed to the reservoir pressure, means connected to the plungers and ada ted to support the rim for a limited circum erential play in either direction "while holding it against lateral thrust, brace means non-rigidly connected to said rim, and dashpots having plungers connected to said brace means and adapted to resist the displacement between the brace means and rim and to transmit traction ull from hub to rim, substantially as descri ed.

15. In a pneumatic Wheel, an outer rigid rim, radial yrigid spokes connected to the rim, pistons loosely connected to the spokes, cylinders having slotted end caps to receive and guide the spokes which are free for a,

limited ci'li'cun'lierential play only, and a hub to receive said pump piston, a valved outlet from the outer end of the barrel into the cylinder below said piston, and an air supply port opening into an intermediate point 1n the pump barrel.

17. In a pneumatic wheel, a rim having spokes and pistons on the inner ends of the' spokes, a hub havin cylinders which receive the pistons and liaving a divided compressed air reservoir communicating with the inner ends of the cylinders, a pumppiston mounted in the inner end of several cylinders, a pump barrel movable With a` piston and adapted to receive each said pump piston, a valved outlet from the outer end of f the barrel into the cylinder below-each piston, an air supply port opening into the inner end of each barrelE said port having an inwardly opening check valve, a loose packing for the outer ends of the cylinders, and means to hold the packing away from said pistons, substantially asv described.

18. In a pneumatic wheel, a rim, a hub, spokes on the rim having pistons, cylinders on the hubs Which receive the istons, a hub reservoir divided to contain different bodies of compressed air to Which the pistons are exposed, said cylinders having outer end caps Which are provided with slots elongated circumferentially of the wheel and adapted to receive the spokes with a close sliding fit, a loose packing in the outer ends of the cylinders, screens to hold the packing from the pistons, said pistons having air inlet ports opening into a pump barrel therein, a pump plunger mounted on lthe hub and movable in said barrels, and an outwardly opening checkvalve controlling the discha of compressed air from each pump barrel mto the hub i reservoir, and relief valves to prevent excessive pressures of said air bodies, substantially as described.

19. A pneumatic wheel comprisin a hub having a divided air reservoir an a rim .having a plurality of radial plunger supports, cylinders opening to the reservoir `pressure and adapted to receive the plungers, means provided for a limited lay of the spokes only in the circumferentiall p ane of the wheel, and means to automatically maintain the reservoir preure by the body movements of the rim, said means comprising pumps Withinl a plurality of said cylinders and operated by the plungers, and

relief valve means for the reservoir, substantially as described.

20. A buoyant wheel comprising a rim,

Aconnected to the inspokes,.pistons looseliyi's, 'yr de f .th

c in rs or e ner ends of the spo pistons, a hub air reservoir into whichV the cylinders are fastened, spiders at the inner ends of the cylinders, and guides on the pistons slidablyifmounted in said spiders.

.21. In a pneumatic wheel, a hub reservoir for compressed air which is divided into independent compartments .adapted to contain oilradial1y disposedfcylinders leading from the marginal periphery of the hub and lair pressure throughout sai having each afree and unobstructed vopening into one of said compartments, the opening being disposed to permit the oil under centrifugal force to freely enter said cylinders, a rim, and rim supporting pistons radially movable in said cylinders.

22. A Wheel of the character described,

comprising'a rim,v spokes connected to the tain the hub air pressure, and means to re lieve excess airl pressure at the hub, substantially as described.

23. In a wheel of the character described, a rim having .spokes connected thereto which have a limited play in the circumferential plane of the rim, pistons of relatively lar diameter as compared with the s okes whlch are loosely connected to the inner ends of the spokes and rovided on their inner ends with guides, ali divided air reservoir, and cylinders' of large diameter at their outer endsand contracted diameter at their inner ends which are made fast to the hub and open into the sub-divi-l sions of said reservoir, bearings for the piston guides in said c linders, and mechanism responsive to the liody movements of the rim relatively to the hub for maintaining a predetermined air pressure in the reservoir, substantially as described.

24. In a wheel of thevcharacter described, i a ,substantially rigid rim, a hub havin means for the storage of distinct bodies o compressed air, a plurality of radial cylinub having a subl ders connected to the hub, and communicating with said air storage means, pistons movable in` the cylinders, rigid s 'okes loosely but positively connected to bot rim 4means responsive to said rim movements to redetermined hub storage automatically maintain a reservoir.

15 spokes loosely but positively 2ory preventing. said 26. In a pneumatic wheel, a hub having radial cylinders mounted thereon, pistons movable in the cylinders, spokes hingedly connecting the rim and pistons, a divided 5 air reservoir at the hub having eachv .portion thereof communicating with several of said cylinders, means to maintain the air pressure in said reservoir by the relative movementbetween hub and rim, and means to transfer pressure gularly except in a circumferential plane of the rim, and means to prevent the turning of said pistons and spokes in their hub supporting means.

28.4In a pneumatic Wheel, a rim, a hub adapted to store separate bodies of oil and compressed air, spoke and hub and comprising cylinders exposed to the hub oil and air storage, pistons4 movable in thel cylinders,V and rigid spokes mounted 0n the pistons and free to have a limited play in the circumferential plane of the Wheel, one or more of said pistons carrying an air pumpin' element of smaller cross sectional area t an the piston, and pump means (so-acting with said element to `charge the hub storage.

29. In a pneumatic Wheel, a substantially rigid. rim, spokes having a positive connection to the rim but capable of a limited angular play in the plane of the rim, hub

`mea-ns for buoyantlyA supporting said spokes Without interference With their said limited play, means for yieldably imparting the traction strains from hub to rim comprising short spokes buoyantly supported on the hub, and yieldable connections from the outer ends of said short spokes to the rim.

In testimony whereof I aflix my signature.

WILLIAM HENRY MQCAFFREY. Witness:

NoMIn WELSH.

means connecting rim 

